But Minio is not a native solution, does not having transfer acceleration functionality provided by S3, and may require constant updates. We really want Azure to support S3 API, or at least some API so that we can enable user's download which only valid for a limited time.

Thank you for your feedback. Unfortunately, we do not plan to add this feature to our platform at this time. We will provide an update if this changes. For any further questions, or to discuss your specific scenario, send us an email at azurestoragefeedback@microsoft.com.

There are a number of solutions that can transparently convert S3 API to Azure Blob API. Just search Azure Marketplace for "S3" and you will see Minio, Flexify.IO and some others. Some of them are available as a service - so no updates are involved.